1. Field of the Invention
This invention relates to a catalyst for purifying exhaust gases which can reduce with high efficiency nitrogen oxides, carbon monoxide and hydrocarbons, the noxious components of exhaust gases from internal combustion engines, etc., and which has high mechanical strength and durability at high temperatures.
2. Description of the Prior Art
Various catalysts have been suggested to date for reducing the noxious components of such exhaust gases as mentioned above. Catalysts containing platinum, palladium or rhodium as a catalyst ingredient supported on an alumina carrier are considered to have a relatively superior purifying activity.
However, these catalysts are still unable to meet the requirements for the purification of motor vehicle exhaust gases because they cannot reduce the aforesaid three noxious components with high efficiency, and do not have superior mechanical strength and durability at high temperatures.
A need therefor continues to exist for a catalyst for the removal of nitrogen oxides, carbon monoxide and hydrocarbons from the exhaust gases of internal combustion engines, which exhibits high efficiency for said removal and exhibits high mechanical strength and durability at high temperatures.